What is the test for obtaining a search warrant for a search conducted without a warrant?

We first observe that it is uncontested that the search was made without a warrant. The search, therefore, is subject to the following basic constitutional[26 Cal.App.3d 816] rule: ". . . searches conducted outside the judicial process, without prior approval by judge or magistrate, are per se unreasonable under the Fourth Amendment--subject only to a few specifically established and well-delineated exceptions.' The exceptions are 'jealously and carefully drawn,' and there must be 'a showing by those who seek exemption . . . that the exigencies of the situation made that course imperative.' '(T)he burden is on those seeking the exemption to show the need for it.' . . .' (Coolidge v. New Hampshire, 403 U.S. 443, 454--455, 91 S.Ct. 2022, 2032, 29 L.Ed.2d 564, 576.)